Air supply apparatus for establishing constant pressure in a receiving enclosure

ABSTRACT

An air supply apparatus is provided for establishing a constant pressure in a receiving enclosure, such as a stomach or the like. Generally, the apparatus includes a supply means for supplying a pressure medium with connecting means being provided for connecting this supply means to the aforesaid enclosure. A timing means is moreover provided which controls the flow of medium through the connecting means to be of pulsed form. The timing means includes detecting means to determine when pressure in the connecting means reaches a predetermined level to deactivate the timing means and terminate the flow of medium through the connecting means. According to one embodiment, the timing means is connected to and controls the supply means which is an air pump. According to another embodiment, the timing means is connected to and controls valve means provided in the connecting means. The detecting means includes a closed casing connected to the connecting means and a fixed contact on the casing, therebeing provided a bellows on the casing and balancing the pressure in the casing with a reference pressure, therebeing furthermore provided a contact displaceable with the bellows to engage the first said contact, and circuit means coupled to said contacts and adapted to control the flow of medium through the connecting means to be of pulsed form. The circuit means includes an RC circuit and a solenoid controlled by the RC circuit to control the supply means. The detecting means may alternatively include a pressure to voltage transducer which operates in connection with a reference voltage to control either the air pump or valve means mentioned hereinabove.

United States Patent [191 Watanabe 1 Nov. 13,1973

[ AIR SUPPLY APPARATUS FOR ESTABLISHING CONSTANT PRESSURE IN A RECEIVING ENCLOSURE [75] Inventor: Daijl Watanabe, Tokyo, Japan [73] Assignee: Kabushiki Kaisha Machida Seisakusho, Tokyo, Japan [22] Filed: Aug. 29, 1972 [21] Appl. No.: 285,097

[30] Foreign Application Priority Data Primary Examiner-Henry T. Klinksiek Att0mey-Eric l-l. Waters et a1.

[57] ABSTRACT An air supply apparatus is provided for establishing a constant pressure in a receiving enclosure, such as a stomach or the like. Generally, the apparatus includes a supply means for supplying a pressure medium with connecting means being provided for connecting this supply means to the aforesaid enclosure. A timing meansis moreover provided which controls the flow of. medium through the connecting means to be of pulsed form. The timing means includes detecting means to determine when pressure in the connecting means reaches a predetermined level to deactivate the timing means and terminate the ,flow of medium through the connecting means. According to one embodiment, the timing means is connected to and controls the supply means which is an air pump. According to another embodiment, the timing means is connected to and controls valve means provided in the connecting means. The detecting means includes a closed casing connected to the connecting means and v a fixed contact on the casing, therebeing provided a bellows on the casing and balancing the pressure in the casing with a reference pressure, therebeing furthermore provided a contact displaceable with the bellows to engage the first said contact, and circuit means coupled to said contacts and adapted to control the flow of medium through the connecting means to be of pulsed form. The circuit means includes an RC circuit and a solenoid controlled by the RC circuit to control the supply means. The detecting means may alternatively include a pressure to voltage transducer which operates in connection with a reference voltage to control either the air pump or valve means mentioned hereinabove.

10 Claims, 4 Drawing Figures Patented Nov. 13, 1973 AIR SUPPLY APPARATUS FOR ESTABLISHING CONSTANT PRESSURE IN A RECEIVING ENCLOSURE FIELD OF INVENTION This invention relates to air supply apparatus for establishing a constant pressure.

BACKGROUND In the case of supplying air to any particular objective such as, for example, supplying air under pressure into the stomach to expand it for medical purposes, if the pressure within that objective reaches a predetermined level, the air supply can be automatically stopped. If the pressure within that objective becomes lower than the predetermined level due to any cause such as air leakage, the air supply is automatically regenerated until the pressure again reaches the predetermined level.

SUMMARY OF INVENTION It is an object of the invention to provide an improved apparatus of the above-indicated type.

One embodiment of the invention is characterized in that an air supply by an air pump coupled through an air supply pipe to an objective section is controlled by a timer to be in the form of pulsation. Further, there is provided a detecting apparatus which responds to the internal pressure of the air supply pipe reaching a predetermined level. The apparatus is so arranged that when the detecting apparatus is operated the timer is inactive and the air supply to the objective section is suspended.

In accordance with the invention there is generally provided an apparatus for establishing a constant pneumatic pressure in a receiving enclosure. This apparatus comprises supply means for supplying a pressure medium, connecting means connecting said supply means to said enclosure, and timing means controlling the flow of said medium through the connecting means to be of pulsed form. The timing means includes detecting means to determine when pressure in the connecting means reaches a predetermined level to deactivate the timing means and terminate the flow of said medium through the connecting means.

According to one embodiment of the invention, said timing means may be connected to and control the supply means. According to another embodiment of the invention, valve means are provided in the connecting means, said timing means being connected to and controlling said valve means.

According to a further feature of the invention, there may be provided additional detecting means coupled to said connecting means to determine when pressure in the latter exceeds a predetermined level and to vent the connecting means thereupon.

According to another feature of the invention, said detecting means may including a closed casing connected to said connecting means, a fixed contact on said casing, a bellows on said casing and balancing the pressure in the casing with a reference pressure, a contact displaceable with the bellows to engage the first said contact, and circuit means coupled to said contacts and adapted to control the flow of medium through the connecting means to be of pulsed form.

According to still another feature of the invention, the aforesaid circuit means may include an RC circuit and a solenoid controlled by the RC circuit to control said supply means or the valve means.

According to still another embodiment of the invention, the detecting means may include a pressure to voltage transducer which balances an amplified voltage representing pressure in the connecting means with a reference voltage to determine whetherv or not the valve means or supply means should be operable.

The above and other features and advantages, as well as objects of the invention, will be understood from the detailed description which follows hereinbelow.

BRIEF DESCRIPTION OF DRAWING The invention will next be explained in greater detail with reference to the accompanying drawings wherein:

FIG. 1 is a system diagram showing one embodiment of this invention;

FIG. 2 is a schematic diagram showing an electric circuit for control of the apparatus of FIG. 1.

FIG. 3 is a diagram showing another embodiment of this invention; and

FIG. 4 is a diagram showing a modified example of a detecting apparatus.

DETAILED DESCRIPTION Component 1 is a constant-pressure type air pump which serves to supply constant-pressure air or pneumatic pressure to an objective section or receiving enclosure A through an air supply pipe 2. The operation of the air pump I is so controlled by a timer 3 that the initiating and stopping of the air supply can be repeated. This type of pulsating air supply is effected such that an air supply time B and an air supply stoppage time B are alternately repeated as shown diagrammatically in FIG. 1.

A sealed casing 4 is provided in communication with the air supply pipe 2, and a bellows 5 provided therein is in communication at its interior with ambient atmosphere. Bellows 5 is provided at its end wall with a con-' tact 6a. Another contact 6b is provided on the casing 4 and faces the'contact 6a. The contact 6b is composed of a screw passing through a wall of the casing 4 so that the distance between the contact 6a and the contact 6b can be adjusted. By these contacts and said bellows, a detecting switch 7 is formed such that normally the two contacts 6a and 6b are in contact with the bellows 5 expanded by the ambient atmospheric pressure.

The control of the operation of the air pump 1 is carried out by the timer 3. As shown in FIG. 2, the timer 3 comprises an RC circuit. When the switch 7 is in its closed condition, a relay L is operated as a result of which a relay contact LS is closed to operate the RC circuit. After the condenser C has been charged by the associated voltage source, a relay L, is energized and thereby a relay contact LS is opened and, at the same time, a contact L8,, is closed. During the succeeding discharge of the condenser C, the relay L, is kept energized and, during this period, the air pump 1 is kept in operation to effect one cycle of air supply 8,.

When the discharge of C is completed, the relay L, is deenergized. The circuit for operating the air pump 1 is then opened to stop the air supply (see 8,) and at the same time the contact L8,, is closed and the RC circuit can again be energized to repeat the foregoing operation. Thus by repeating the air supply cycle of B, and 8,, an air supply of pulsation form is obtained to the objective section A. The supply air amount can be determined by changing the time constant of the RC circuit. However, when the detecting switch 7 is open, the RC circuit does not operate and air supply by the air pump 1 is not effected.

In the above apparatus, an orderly pulsed air supply to the objective section A is continuously effected by the intermittent driving of the air pump 1. Thereby, the pressure within the objective section A and also the pressure within the air supply pipe 2 are gradually increased to a certain level. Thereafter, during each air supply pulse time B,, the pressure within the pipe 2 instantaneously reaches such predetermined level and the bellows 5 contracts against the action of the atmospheric pressure so that the detecting switch 7 is opened and the air supply is suspended. During this suspension period, the bellows 5 is restored to its initial expanded condition and the detecting switch 7 is again closed to resume the pulsed air supply operation. Thus, the pulsed air supply and the suspension of the same are effected. Accordingly, as time goes by, the difference between the internal pressure during the air supply time B and during the air supply stoppage or suspension time gradually becomes smaller, so that the time period required for restoration of the closing of the detecting switch 7, that is, the suspension time, gradually becomes longer. If this is repeated and finally the internal pressure of the objective section A reaches the predetermined level, the detecting switch 7 is finally maintained in its open condition to maintain suspension of the pulsation air supply to the objective section A. Thus bursting of the objective section A caused by excess pressure can be prevented.

When the objective section A is a stomach or the like, after it has been once supplied with air so that the internal pressure thereof reaches a predetermined level, because the stomach is in communication with other internal organs, the pressure is gradually lowered. When it goes below the predetermined leverl, the detecting switch 7 is closed and the pulsed air supply is again effected. Thereafter, the air supply operation is automatically stopped when the pressure reaches the predetermined level. The predetermined level can be selected byv adjusting the distance between the contacts 6a and 6b by threaded adjustment of the contact 6b.

In anticipation of the occurrence of an extraordinarily high pressure within the objective section A for no apparent reason, another detecting switch 8 of the same construction as the detecting switch 7 is provided connected to the air supply passage. The pressure capable of opening the switch 8 is selected to be higher than that for the detecting switch 7. When the switch 8 is operated, an electromagnetic valve 9 interposed in a discharge pipe 10, which diverts from the air supply pipe 2, is opened for discharging air and reducing the high pressure which has developed in the objective section A.

In the above example, the air pump 1 is directly controlled by the timer 3 to effect the pulsed air supply. In the example shown in FIG. 3, an electromagnetic valve 11 is interposed in the air supply pipe 2 connected to the discharging side of the air pump 1, the valve 11 being so arranged that a pulsed air supply is effected by opening and closing of the valve 11 under control of the timer 3. The opening and closing of the valve 11 is effected in almost the same manner as in the foregoing example, the air pump 1 of P16. 2 being replaced by the electromagnetic valve 11 in its connectionfwith timer 3.

Instead of the detecting switch 7 comprising the con tacts 6a and 6b as in the above examples, a pressure detecting transducer as shown in FIG. 4 can be used. In this case, the pressure within the pipe 2 is transduced into a voltage by a combination of bellows 5 and a differential transformer. The voltage thus obtained is compared with the reference voltage after it is amplified. During the time when the amplified voltage is below the reference'voltage, the timer 3 is operated by an output from a comparison circuit so as to effect the pulsed air supply. When the amplified voltages becomes higher than the reference voltage, there is no output from the comparison circuit and the timer 3 is put into its inoperative condition and the pulsed air supply is suspended. The differential transformer cornprises a primary winding P and a secondary winding S. A rod-shaped core D moving with the bellows 5 is inserted between the windings P and S. The secondary winding S comprises two windings S and S connected in series in bucking relationship. The result is that the movement of the core D is converted to a corresponding voltage in well known manner.

A further modification is one in which there is additionally provided a counting apparatus system for the timer 3. The number of air supply operations is counted and thereby the amount of supplied air to the objective section A can be measured.

It has been usual hitherto with this kind of air supply apparatus that a detecting pipe is provided separately from the air supply pipe so that a continuous air supply may be effected through the air supply pipe while the interior pressure is detected through the detecting pipe. This conventional apparatus is defective not only in that the construction thereof is complicated due to the fact that two pipes are provided, but also in that, when the detecting pipe is obstructed, continuousair supply is effected and as a result an excessively high pressure can be inadvertantly brought about and the danger caused thereby cannot be avoided.

According to this invention, however, only a single air supply pipe is used and a pulsed air supply is effected. Furthermore, it is so arranged that the air supply is effected while the internal pressure is detected during stoppage time, and the air supply is automatically suspended when the detected pressure reaches a predetermined level. The constructions of the inventions are extremely simple and the operation thereof is easy and safe.

What is claimed is:

1. Apparatus for establishing a constant pneumatic pressure in a receivingenclosure, said apparatus comprising supply means for supplying a pressure medium, connecting means connecting said supply means to said enclosure, and timing means controlling the flow of said medium through the connecting means to be of pulsed form, said timing means including detecting means to determine when pressure in the connecting means reaches a predetermined level to deactivate said timing means and terminate the flow of said medium through said connecting means.

2. Apparatus as claimed in claim 1 wherein said timing means is connected to and controls said supply means.

3. Apparatus as claimed in claim 1 comprising valve means in said connecting means, said timing means being connected to and controlling said valve means.

4. Apparatus as claimed in claim 1 comprising further detecting means coupled to said connecting means to determine when pressure in the latter exceeds a predetermined level and to vent the connecting means thereupon.

5. Apparatus as claimed in claim 1 wherein said detecting means includes a closed casing connected to said connecting means, a fixed contact on said casing, a bellows on said casing and balancing the pressure in the casing with a reference pressure, a contact displaceable with the bellows to engage first said contact, and circuit means coupled to said contacts and adapted to control the flow of medium through the connecting means to be of pulsed form.

6. Apparatus as claimed in claim 5 wherein said circuit means includes an RC circuit and a solenoid controlled by said RC circuit to control said supply means.

7. Apparatus as claimed in claim 3 wherein said detecting means includes a closed casing connected to said connecting means, a fixed contact on said casing, a bellows on said casing and balancing the pressure in the casing with a reference pressure, a contact displaceable with the bellows to engage first said contact, and circuit means coupled to said contacts and adapted to control the flow of medium through the connecting means to be of pulsed form.

8. Apparatus as claimed in claim 6 wherein said circuit means includes an RC circuit and a solenoid controlled by said RC circuit to control said valve means.

9. Apparatus as claimed in claim 1 wherein said detecting means includes a pressure to voltage transducer.

10. Apparatus as claimed in claim 1 wherein said supply means is an air pump. 

1. Apparatus for establishing a constant pneumatic pressure in a receiving enclosure, said apparatus comprising supply means for supplying a pressure medium, connecting means connecting said supply means to said enclosure, and timing means controlling the flow of said medium through the connecting means to be of pulsed form, said timing means including detecting means to determine when pressure in the connecting means reaches a predetermined level to deactivate said timing means and terminate the flow of said medium through said connecting means.
 2. Apparatus as claimed in claim 1 wherein said timing means is connected to and controls said supply means.
 3. Apparatus as claimed in claim 1 comprising valve means in said connecting means, said timing means being connected to and controlling said valve means.
 4. Apparatus as claimed in claim 1 comprising further detecting means coupled to said connecting means to determine when pressure in the latter exceeds a Predetermined level and to vent the connecting means thereupon.
 5. Apparatus as claimed in claim 1 wherein said detecting means includes a closed casing connected to said connecting means, a fixed contact on said casing, a bellows on said casing and balancing the pressure in the casing with a reference pressure, a contact displaceable with the bellows to engage first said contact, and circuit means coupled to said contacts and adapted to control the flow of medium through the connecting means to be of pulsed form.
 6. Apparatus as claimed in claim 5 wherein said circuit means includes an RC circuit and a solenoid controlled by said RC circuit to control said supply means.
 7. Apparatus as claimed in claim 3 wherein said detecting means includes a closed casing connected to said connecting means, a fixed contact on said casing, a bellows on said casing and balancing the pressure in the casing with a reference pressure, a contact displaceable with the bellows to engage first said contact, and circuit means coupled to said contacts and adapted to control the flow of medium through the connecting means to be of pulsed form.
 8. Apparatus as claimed in claim 6 wherein said circuit means includes an RC circuit and a solenoid controlled by said RC circuit to control said valve means.
 9. Apparatus as claimed in claim 1 wherein said detecting means includes a pressure to voltage transducer.
 10. Apparatus as claimed in claim 1 wherein said supply means is an air pump. 